* Silicon dioxide (SiO2) is a network covalent solid. This means it forms a giant, three-dimensional structure where silicon atoms are bonded to oxygen atoms in a continuous network. These strong covalent bonds require a lot of energy to break, resulting in a very high melting point (around 1713°C).
* Methanol (CH3OH) is a molecular compound held together by relatively weak intermolecular forces (hydrogen bonding). These forces are much weaker than the covalent bonds in SiO2. Consequently, methanol has a much lower melting point (-97.6°C).
In summary:
* Silicon dioxide (SiO2) - High melting point due to strong covalent bonds.
* Methanol (CH3OH) - Low melting point due to weak intermolecular forces.
